Environmental Effects

From Epic Path
Jump to navigation Jump to search
Lucky I bought that ivory comb. This is really going to mess up my hair.

The world is a dangerous place for an adventurer. Buildings collapse, fires happen, sewers and bogs must be slogged through, avalanches and storms and eruptions abound. Many adventurers have gotten lost in trackless wilds or been swept away by flash floods or fallen victim to deadly weather or even quicksand. It's enough to make you want to stay in bed....

The following rules give guidelines on running adventures in a hostile world. In general, any level of sturdy shelter is enough to halt environmental effects, no matter how crude. A cave serves nicely, and even a simple overhang will serve, based upon the GM's rulings, of course. Many items and spell effects that provide shelter also stop all environmental effects. Portable shelter, such as camp fires and tents, are not nearly as good, but still far better than nothing, and a tent combined with sturdy clothes appropriate to heat or cold can make the wilderness...not cozy, but much less dangerous.

NOTE to GM's: The Environment rules are optional, but provide a great way of creating a real 'survival horror' experience if you're running a low-level, low-power 'grime and guts' sort of a campaign. Indeed, the whole 'Grim World' power level pretty much cries out for the Environmental Effects rules, to make it truly, perfectly awful.

However, approach with caution! Even high-powered, well-equipped adventurers that are not prepared for environmental effects can find themselves in a lot of trouble very quickly if they aren't used to it. Since environmental damage is often a constant, recurring source of damage, even extremely mighty parties can find themselves in trouble quickly. This might be the effect you're after, but be careful! Also, be wary of the scaling of environment effects, especially the Falling Object rules. Giant toppling trees are extremely deadly, which is what you would expect from dropping a Redwood on somebody, and avalanches and tsunamis and pyroclastic flows are just utterly unfair. Use these things sparingly...unless your campaign is into such things, of course.

Monsters and the Environment

Players have to suffer all these terrible effects...but what about monsters?

For simplicity, it is assumed that all monsters have enough resistance to Environmental damage that they never take effects from their usual environment. A tribe of orcs that lives atop the highest peak in the land just completely ignore the cold, thin air, constant scouring of icy needles, and all ill effects of the brutal winds.

This is totally unfair, but that's how it works. As a consolation, all the environmental effects that deal lethal damage, such as falling objects or avalanches, affect monsters just like they do characters.

Environmental Damage

Hazardous environments can inflict damage to characters attempting to pass through them. Environmental damage is treated like any other kind of damage, except that it is damage caused by some natural condition or effect of the world, and not caused by magic, or the intent and planning of an individual or group. If you possess some means of mitigating the damage type being inflicted (such as by having some ER or DR suitable for the damage type), environmental damage is reduced exactly like normal damage.

In addition, some equipment specifically provides resistance to environmental damage, while providing no resistance to normal damage. An example of this is a tent, which reduces environmental damage by 5 points. This is treated as ER 5/- and DR 5/-, but only for purposes of resisting damage caused by environmental effects. This means an accidental rockslide will have its damage reduced by the tent, but if a mountain troll throws a rock at the tent, the tent provides no protection at all.

Note that falling and collision damage are not considered environmental damage, even if they are caused by an environmental effect (e.g., you get pushed off a cliff by a flooding river). These types of damage are resolved using their own rules.

Endurance Feat

Special mention must be made of the Endurance (Feat). This feat gives you resistance to environmental damage. Endurance lets you basically ignore the effects of environmental cold and heat once you get high enough level, and that is exactly how it is intended to work. In harsh climate campaigns, it can be amazingly useful.

Firewood and Camp Fires

Firewood is used to build a campfire, which requires Flint and Steel or some other means of creating fire.

A campfire occupies one square, inflicts Singed doing fire damage to anyone who enters that square, and removes cold weather Environmental Effects in a 15 foot radius (a 7x7 square space), as well as allowing the ability to cook food and providing endless hours of entertainment to anyone who cares to watch.


A tent of any size provides 5 points of resistance to environmental damage. Note that, like Endurance, this applies even to characters who have fallen unconscious (indeed, that's kind of the point of tents). Bundling your heat-stroked sorcerer into a tent to cool them down a bit is a good way to save their life.


Armor isn't just good against getting shot with a crossbow bolt or bouncing off Purple Worm bites, many types of armor also offer some basic protection against either hot or cold conditions. See the individual armor descriptions for more details, but don't be surprised that if Environmental Effects are in play, suddenly there's a LOT more types of armor that seem pretty good...depending on the weather.

Stacking of Environment Effects

These effects are described in a modular fashion, so that if the GM is feeling especially cruel, they may stack them up. A classic example is the top of an extremely high mountain. If the maximum realism is desired, such an environment would offer Severe Cold or worse, High Altitude effects for higher than 15,000 feet, and almost certainly Windstorm conditions or worse, with a Sandstorm effect of needle-sharp ice crystals, to boot. To say that such an environment is extremely hostile is putting it mildly, and we haven't even left the nice soft, cozy confines of the Prime Material Plane yet!

In general, GMs should stack environmental effects to any degree they wish and that makes sense for their campaign. Heat and Cold effects at the same time would be hard to justify unless something very bad is happening (like a volcano erupting up through a glacier, which actually happens in real life and is just as bad as you think), but heat, hurricane winds, and heavy rain combined together work just fine.

The one rule to live by is that all applicable environment effects are applied separately, not additively. The damage of all effects are applied separately, so suffering from cold and high altitude means you suffer two doses of environment damage, which can separately be resisted by any gear, feats, or effects. GMs should resist the urge to 'stack these up', unless they are running a gritty, nasty, survival-horror type game. If that's what your table is after, then go for it!

Environmental Effects as Encounters

The GM may rule that any or all unusual environmental effects count as an encounter for calculating the duration of spells and other effects. A blustery, windy day does not usually count, but getting hit with an avalanche or a flash flood usually does count, and the effects of a volcano... might, depending upon circumstances. If a volcano makes the world so nasty it ends your spell effects every hour or two, well, that's just part and parcel of the terrible majesty of nature! As always, the GM adjudicates all such circumstances.

Scaling of Environmental Effects

GMs may choose to increase the scaling of environmental damage as a way of providing more challenge to their players. Increasing damage to 2d6 or 3d6 per interval can place appropriate levels of stress upon player resources. Note that healing spells and class features normally heal environmental damage at the same rate as they heal any other damage. A very effective stressor is to rule that environmental damage is no longer affected by healing spells, or even no longer affected by anything except for rest. As always, all such adjustments are up to the GM, but approach with care!

Beneficial and Fantastic Environmental Effects

Most of these rules are aimed at fairly mundane and quite dangerous aspects of the environment. Falling objects, cold weather, wildfires, avalanches and collapses, are all things that are depressingly common in the 'real world.' But this is a game, and YOUR game environment doesn't have to follow the mundane rules all that closely if you don't want it to. Towering and majestic trees, ancient groves full of peaceful life, magical forests, blessed meadows, healing and wondrous springs, highly integrated ecosystems, all these things and many more can be used to add many new and unusual effects to the environment, both for good and for ill.

If you want to design a custom environment effect for your game, we strongly advise that you lay out for the players what unusual effects exist and what they do, IF the characters could reasonably know about them in advance. We don't need to explain what a falling object is, since such things are very familiar to the players from the real world, but if you decide to incorporate Basilica Grass as a common feature, well, you need to explain what Basilica Grass does, assuming the characters would know what it is.

Some quick examples to set the mood:

  • Basilica Grass grows incredibly quickly, to waist height in a single evening, but it is extremely fragile, crumbling to dust with a touch. Adds bonuses to concealment and tracking, but does 1d6 points of poison (physical, uncommon) as environmental damage each hour, due to allergenic dust coating EVERYTHING.
  • Mallorn Groves are composed of weirdly twisting Mallorn Trees, which catch the wind and make random musical sounds. Scares away predators, and thus adds bonuses to survival skill to forage for food, but creates random squares of difficult terrain from the twisting, entwining growth.
  • Ghost Fronds are tall, eerily glowing plants that give off dim light in a ten foot radius. They are ethereal plants, which weirdly bridge the Material Plane, and are animated to boot. They move on their own, angrily lashing at motion near them, which is harmless to material creatures but dangerous for ethereal beings. They grant light in the darkness and drive away all ethereal creatures, but inflict the Distracted condition at the beginning of any combats.
  • Forgewood Trees are sturdy, gnarled trees that glow orange with their internal heat. Their thick, gnarled bark is warm to the touch, and they radiate heat as a campfire, negating cold environmental effects in a ten-foot radius. Touching or climbing one inflicts Singed (as fire damage), as a campfire does, and being in a Forgewood Grove in hot weather doubles all hot weather environmental damage.
  • Wolframith Trees are weird, skinny trees with bright silver leaves that distill death aura from sunlight, and are killed by water. They inflict 1d6 points of threnodic (energy, rare) damage per minute as environmental damage, but only during daylight and only if they have line of sight to a creature. At night, they are harmless.
  • Floating stones can be found in flat wastelands, and are exactly what they sound like, rocks that float. The create a 3 dimensional terrain, with large stones filling one or more squares and being perfectly solid to walk upon. At night, if the winds and other conditions are just right, they move around. Can have many effects, left to the GM to interpret.

As can be seen, many weird and interesting effects can arise from magical, wondrous, and fantastic environments.

Extra-Planar Environmental Effects

All of the rules in this page are written with the assumption that the action is happening on the Prime Material Plane, or at least a Material Plane. This means "The World", no matter how magical and fantastic it may be, is fairly recognizable and acts 'normally'. But as we all know, as those pesky players get more advanced, they will eventually find themselves in another plane.

And inevitably, bad things will happen there.

So, how do you adjudicate it when a building in the The City of Brass collapses on top of your heroes? Obviously, that's a simple Collapse, as covered below, but shouldn't the fact that it happens in a building made of red-hot metal, in the Plane of Fire, where the air is literally ON FIRE, have some impact?

Of course it does!

Simply put, environmental effects that occur on planes other than your native conditions are far more harmful than otherwise. This is simulated by adding a modifier to all damage dice caused by environmental effects based upon 'how far out' the Plane happens to be.

The First World, for example, is the Material Plane closest to the Prime Material, and so, an avalanche there looks very similar to one on the Prime material, it's just that all the rocks break into razor-sharp jagged chunks, because that is simply the nature of reality there. As a result, all environmental damage in the First World has a +1 per die damage modifier.

The further you go 'out into the cosmos', the worse it gets.

For simplicity, here are some guidelines for adventurous GM's to follow.

Extraplanar Environmental Modifiers =
  • On a different but similar plane of existence: The Ether, the Plane of Shadow, The First World, etc. +1 to each damage die
  • On a different but non-hostile plane of existence: The Plane of Air, Elysium, The Silver Fields, etc. +2 to each damage die
  • On a wildly different plane of Existence: The Azure Sea, The Plane of Earth, the Plane of Water, etc. +3 to each damage die
  • On a wildly different and hostile plane of existence: The Plane of Fire, the Nine Hells, the Abyss, etc. +4 to each damage die
  • Very Bad Places: The Sunward Reaches, The Infinite Well, Temperest, Hellcore, Lavarna, etc. +5 to each damage die
  • The Edge of Reality: Apocolyptica, The Outer Dark, The Fount of Reality, The Nascent Seed, etc. +6 to each damage die

Environmental Effects

Altitude and Inimical Gases

High altitude travel can be extremely fatiguing – and sometimes deadly – to creatures that aren't used to it. Cold becomes extreme, and the ill-suited sustenance in the air can wear down even the most hardy of warriors.

Acclimated Characters: Creatures accustomed to high altitude generally fare better than lowlanders. Any creature which has spent at least a month of its life in high altitudes, or has a racial disposition towards high altitudes, is considered acclimated. Acclimated creatures gain a bonus to resist the effects of high altitudes. Undead, constructs, and other creatures that do not breathe are immune to altitude effects.

Altitude Zones: In general, mountains present three possible altitude bands: low pass, low peak/high pass, and high peak.

  • Low Pass (lower than 5,000 feet): Most travel in low mountains takes place in low passes, a zone consisting largely of alpine meadows and forests. Travelers might find the going difficult (which is reflected in the movement modifiers for traveling through mountains), but the altitude itself has no game effect.
  • Low Peak or High Pass (5,000 to 15,000 feet): Ascending to the highest slopes of low mountains, or most normal travel through high mountains, falls into this category. Most creatures labor to breathe in the thin air at this altitude. Each hour spent traveling at this altitude inflicts 1d6 points of environmental damage due to exposure. Furthermore, characters may only travel at this altitude a number of hours equal to their CON modifier before becoming fatigued. The fatigue ends after a full night's rest, or when the character descends to an altitude with more air. Acclimated characters can travel at this altitude for an additional 4 hours before becoming fatigued, and can reduce the environmental damage by 1 point per hour.
  • High Peak (more than 15,000 feet): The highest mountains exceed 15,000 feet in height. At these elevations, creatures are subject to both high altitude fatigue (as described above) and altitude sickness, whether or not they're acclimated to high altitudes. Altitude sickness represents the inimical nature of such heights to normal life, and affects mental and physical prowess. Each hour spent traveling at this altitude, characters suffer 3d6 points of cold (energy, common) as environmental damage due to exposure, and must make a Might check versus a Challenging DC for their level or become Exhausted. The exhausted condition persists until a full night's rest. Creatures acclimated to high altitude receive a +4 competence bonus on their might checks to resist altitude sickness, and can reduce the environmental cold damage by 1 point per hour, but eventually even seasoned mountaineers must abandon these dangerous elevations.

Inimical Gases

The High Altitude rules can easily be expanded to include all cases where the air is less than nice. This can be dense layers of swamp gas clinging heavily to the lungs of feckless explorers, it can be a bad case of 'mine damp' smothering those who wander into it, it can be a magical effect in an Alchemists' lab where the air around a bubbling cauldron is no longer the right kind of air, it can be due to Planar effects leaking into the Prime material, or cloying shadowstuff clogging the lungs in a dark barrow, and many other things besides.

All such effects can be attributed to a similar High Altitude effect and run with the same rules. High Pass or High Peaks are obviously the most common settings for Inimical Gases, and make excursions into old abandoned mines full of black damp very, very dangerous. For VERY highly noxious environments, the amount of damage can be increased by 1d6, 2d6, or even 3d6 per hour. For places where the air is densely fouled, the frequency of the check can be increased to every half hour, or even every ten minutes. If the GM is feeling particularly cruel, do both! The inside of a volcano is a classic place where the noxious fumes choking the air may inflict 3d6 to 6d6 of poison (physical, uncommon) as environmental damage every ten minutes, and that's on top of the Heat or Wildfire conditions. Yikes! Whether or not it is possible to have acclimated creatures to such effects is up to the GM, but it certainly works to have a tribe of specially adapted Fire Trolls living in the volcano....


Avalanches are a deadly peril in many mountainous areas. While avalanches of snow and ice are common, it's also possible to have an avalanche of rock and soil, or bile and bone marrow, or tormented souls, or many other things, depending upon where exactly you are.

An avalanche can be spotted before it hits with an Average DC check against the CR of the area in which the avalanche is encountered. Higher CR terrain is considered to be higher, steeper, and generally less forgiving than lower CR terrain.

An avalanche inflicts damage as a collision to all creatures caught in its path, but an avalanche does not have a given "speed", instead assumed to be moving 'really, REALLY, fast.' You cannot outrun an avalanche, ever, although you can generally fly above one if you are quick and lucky. The GM adjudicates how 'tall' an avalanche is, but generally it's between 5 and 30 feet. An avalanche, since it does not have a speed to measure the collision damage, does 1d6 points of bludgeoning (physical, common) as environmental damage per CR of the area the avalanche is located within. Affected creatures are allowed either a Reflex or Fort save to reduce this damage by half. The DC of this check is an Impossible Save versus the CR of the area. Those who fail their saves are buried.


Buried characters gain the pinned condition unless they have Burrow, Earth Glide, Swim, or some other way of moving, and take 1d6 points of crushing (physical, common) as environmental damage per minute. If a buried character falls unconscious, their hit points are immediately set to negative 1 and they must begin making death saves. Yikes! If you are buried by a Flash Flood, Lava Flow, or Tsunami, you don't even have that much time, and go straight to Suffocation.


Creatures buried in an avalanche (or a tsunami, or a flash flood, or a collapse, or a pyroclastic flow, or a lava flow, see below) are generally helpless, because they are pinned or unconscious or worse. To dig a buried creature free, the best plan is to have someone with an appropriate Move speed simply go get them. Burrow is always usable on solid material, and Swim is always effective on liquids. Pyroclastic Flows or lava flows may be traversed with one or both, depending upon circumstance and the GM's decisions. Rescuers are subject to normal effects according to the type of event. Rescuing a friend from a lava flow by Swimming down to them is incredibly brave, but also extremely painful. See Lava for details.

If nobody has a usable Movement type, then Might skill rolls against a Hard DC for the CR of the event can clear a five foot space of solid material by enough to extract a victim. Exceeding the roll by five or more allows another five feet to be cleared for each five by which the roll was exceeded. Acrobatics is useful to extract victims from non-solid materials. In all cases, even a Pinned victim may attempt an Escape Artist roll against the same DC to get themselves loose, worming their way five feet closer to freedom by every five they make their Escape Artist roll. If you are unconscious or worse, you have no recourse, sadly. Hope that you have friends nearby. Note that a Sending spell cast by a non-pinned person can be a life-saver!


Surprisingly enough, Earthquakes just aren't that bad if you are on reasonably level terrain without high trees. During the actual trembling of the earth, all surfaces are treated as difficult terrain. The shaking doesn't last very long, no more than 1 to 6 minutes, and then its over.

Now, if you are in some terrain besides level open ground, THEN it gets nasty.

Earthquakes generally cause trees or other tall things to fall over, at GM discretion. It's almost always at least one falling object, and can be more. See the Falling Objects rules for the joy of having a tree fall on you. Earthquakes also trigger avalanches. Luckily, in the mountains it's just a plain old avalanche. If you're near a body of water, there may be a tsunami, which is an avalanche of water and even worse than a regular avalanche. Earthquakes often presage the birth of a volcano, which is especially un-fun if it starts dropping lava bombs and pyroclastic flows at random intervals.


If you are underground, in a building in a city, exploring the hollow bones of a Garuda Bird, or any other circumstance other than open terrain, then it is possible for there to be a collapse, with or without an earthquake. A collapse is an avalanche, usually of the surrounding material, with a penalty to the saving throw of -1 to -4 or maybe even more depending on circumstances. If you're Squeezing your way down a six-inch wide crevice a mile underground and the crack suddenly slams shut, you're pretty much done for, although the GM who would put you in such a situation should get an Honorable Mention. Just, like, wow.

It's also possible for there to be a Flash Flood in a cave after an Earthquake, or even a pyroclastic flow blasting along after the baby volcano next door introduces itself. Being in a city with collapsing buildings is also treated as a avalanche, with no modifier to the save if you're outside a building and modifiers as above if you're inside.


An unprotected character in cold weather (a freezing day in a normally temperate clime) must make a fortitude save each hour (Average DC for the CR of the area, +1 per previous check) or take 1d6 points of cold as environmental damage. Characters wearing light or normal clothing or light armor of any sort take a -4 penalty on their saves unless the armor or clothing specifically states otherwise.

A character cannot recover from the damage dealt by a cold environment, nor get rid of the fatigued condition, until they get out of the cold and warm up again.

In conditions of severe cold or exposure (a normal day in an arctic area or a cold desert) an unprotected character must make a fortitude save once every 10 minutes (Average DC for the CR of the area, +1 per previous check), taking 1d6 points of Cold damage on each failed save.

Extreme cold (a really cold day in an arctic area or cold desert) an unprotected character must make a fortitude save once every minute (Average DC for the CR of the area, +1 per previous check), taking 2d6 points of Cold damage on each failed save. Even if they succeed on the save, they take half damage.

Movement on Ice

Characters walking on ice must spend 2 squares of movement to enter a square covered by ice, and the DC for Acrobatics checks increases by +5. Characters in prolonged contact with ice might run the risk of taking damage from severe cold.


Darkness applies to visual senses. Non-visual senses pierce it completely, and may be used in darkness to provide normal function.

Darkvision allows many characters and monsters to see perfectly well without any light at all, but characters with normal or low-light vision can be rendered completely blind by putting out the lights. Torches or lanterns can be blown out by sudden gusts of subterranean wind, magical light sources can be dispelled, or magical traps might create fields of impenetrable darkness.

In many cases, some characters or monsters might be able to see while others are blinded. For purposes of the following points, a blinded creature is one who simply can't see through the surrounding darkness.

Creatures blinded by darkness lose the ability to deal extra damage due to precision (for example, via sneak attack).

Creatures in darkness are immune to gaze attacks.

A creature blinded by darkness can make a Perception check as a free action each round in order to locate foes (DC equal to opponents' Stealth check result). A successful check lets a blinded character hear an unseen creature 'over there somewhere.' It's almost impossible to pinpoint the location of an unseen creature. A Perception check that beats the DC by 20 reveals the unseen creature's square (but the unseen creature still has total concealment from the blinded creature).

Falling Objects

Just as characters take damage when they fall more than 10 feet (see Falling Down), so too do they take damage when they are hit by falling objects. Note that environmental falling objects are slightly different than deliberately thrown or dropped objects, such as those goblins dropping a tree-trunk on you.

These results are handled as Collisions, with the speed of the falling object equal to the distance it fell. Thus, an object falling 50 feet hits with a speed of fifty, inflicting 5d6 of damage. Like falling creatures, the maximum speed of a falling object depends upon the local conditions. The Prime Material Plane usually has a maximum falling speed of 200, inflicting 20d6. This basic result is modified by the size of the falling object:

Table: Damage from Falling Objects
Object Size Damage
Tiny +1d6
Small +2d6
Medium +3d6
Large +5d6
Huge +8d6
Gargantuan +13d6
Colossal +21d6
Titanic and larger +34d6

The nature of the object can raise or lower this damage. A nice, soft mass of falling feathers might do -2 points per die, while loose brush and debris does -1 per die. Falling objects that are exceptionally dense, strong, and hard, like solid boulders, might inflict +1 points per die, while objects specifically intended to cause harm in a fall, like pointy stone stalactites, a portcullis, or a pile driver, might inflict +2 points per die.

Falling Objects always hit, and often hit an entire area, so the victims of such things are allowed a reflex saving throw, against an Average Save DC for the CR of the area, or their own CR, whichever is higher. Making this save reduces the damage by half.

The GM is encouraged to adjudicate all such encounters with an eye towards fun. After all, a wagon-load of feathers is just a recipe for hilarity.


Nothing will put some tension into a game like a raging prairie fire sweeping over the horizon! Wildfires can happen in many ways, such as vast forest fires, volcanoes huffing out pyroclastic flows, the dawning of Furnace, enemy actors setting blazes, and many other things beside. Once a large fire gets going, its nearly unstoppable and unbeatable, so the players just have to deal with it, rather than fight it.

The leading edge of a fire (the downwind side) can advance faster than a human can run (assume 120 feet per round for winds of moderate strength). The exact speed of any fire is left to the GM to determine, and can be fairly slow to incredibly fast. Hey, at least Wildfire HAS a speed, unlike avalanches.... Note that it is not possible to fly over a Wildfire! Such large fires have heat and smoke that reach essentially so high that you will start suffering from altitude exposure (see above) before you get out of the wildfire effects. Nasty!

Within the bounds of a wildfire, a character faces three dangers: fire damage, burning, and smoke inhalation:

Fire Damage

Getting caught within a wildfire is even worse than being exposed to extreme heat. Breathing the air causes a character to take 1d6 points of fire damage per round (no save). Whether any ER is effective against this damage is left to the GM, and should be matched to the source of ER and the actions of the player. A sturdy Fighter whose shield is enchanted against Fire would gain no protection...unless they hunkered down and covered their head and body against the heat as much as possible with the shield, thus filtering the air through its protections.


Characters engulfed in a wildfire suffer the Burned condition, with the CR determined by the CR of the area being travelled through. This condition cannot be removed until they are out of the area of the wildfire. This damage can always be resisted, thankfully.

Smoke Inhalation

Wildfires naturally produce a great deal of smoke. A character who breathes heavy smoke takes 1d6 per round of winded damage. Whether any DR resistances are effective, again, is up to the GM and the actions of the players. Yes, a Wildfire inflicts both Energy and Physical damage. Try not to get caught in huge fires, or be very well-protected!


Environmental heat deals fire (energy, common) as environmental damage that cannot be healed from until the character gets cooled off (reaches shade, survives until nightfall, gets doused in water, is targeted by Endure Elements, and so forth).

A character in very hot conditions (a hot day in a usually temperate clime) must make a fortitude saving throw each hour (Average DC for the CR of the area, +1 per previous check) or take 1d4 points of fire (energy, common) as environmental damage. Characters wearing heavy clothing or armor of any sort take a -4 penalty on their saves unless the armor or clothing specifically states otherwise.

In severe heat (a normal day in a hot desert or a jungle), a character must make a fortitude save once every 10 minutes (Average DC for the CR of the area, +1 per previous check) or take 1d4 points of Fire as environmental damage. Characters wearing heavy clothing or armor of any sort take a -4 penalty on their saves.

Extreme heat (air temperature over 140 degrees F, fire, steam clouds, heavy smoke) a character must make a fortitude save once every minute (Average DC for the CR of the area, +1 per previous check) or take 2d4 points of Fire as environmental damage. Characters wearing heavy clothing or armor of any sort take a -4 penalty on their saves. Even on a successful saving throw, the character takes half damage.

Note that in most cases, environmental heat on a material plane ends when the sun goes down...although in many environments, that just means you now have to endure Environmental Cold. It is possible to encounter extreme heat that lasts through the night, but such things are rarer on the Prime Material Plane.


Wind is probably the most common sort of environmental effect, at least in most environments where your players are likely to find themselves. Wind in air can happen almost literally anywhere, be it the trade winds, a brisk day, a sudden thunderstorm gusting away, a hurricane scrubbing the world flat, an opened door letting the air out of a dungeon into the Deep Dark, etc, winds in air are super common. Wind effects can also represent any large flow of substance the players are embedded within. Winds of Ether, or flows of the Silver Sea, can be modeled as Wind. Flows of Darkness or Shadow, the blazing gush of Fire in the Plane of Fire, stupendous masses of migrating insects, the Tide Of Souls in the Celestial Cascade, all these things and many more can be modelled as Wind effects.

Even plain-old wind made of air might also be carrying smoke, allergenic pollen, or poisons, along with scents that may give warning or give the players away. The wind can create a stinging spray of sand or dust, fan a large fire, keel over a small boat, and blow gases or vapors away. If powerful enough, it can even knock characters down (see Table: Wind Effects), interfere with ranged attacks, impose penalties on some skill checks, and by far the worst of all, force spell-casters to make rolls to successfully cast their spells, which can be very, very dire indeed.

Note that plain old Wind includes light to moderate rain, but not heavy rain or nastier things being blown about, or the violent effects of a thunderstorm. See below for such pleasantries. Beware the trees!

Table: Wind Effects

Wind Force Wind Speed Careful Physical Actions Penalty1 Powerful Physical Actions Penalty1 Checked Size2 Blown Away Size3 Exposed Movement Penalty
Light 0 to 10 mph -0 -0 none none none
Moderate 11 to 20 mph -0 -0 Fine none none
Strong 21 to 30 mph -1 -0 Tiny Fine See Movement
Severe 31 to 50 mph -2 -0 Small Tiny See Movement
Windstorm 51 to 74 mph -3 -1 Medium Small See Movement
Hurricane 75 to 174 mph -4 -3 Large Medium See Movement
Tornado 175 to 300 mph -6 -5 Huge Large See Movement
1   Physical actions are any action that requires a physical component that can be disrupted by high winds. These are separated into 'careful' and 'powerful' actions. Examples of careful actions include ranged weapon attacks, physical skills such as Perception, Sleight of Hand, and Perform, casting a spell with a verbal or somatic component, etc. Powerful actions include siege weapon attacks, massive ranged weapon attacks, physical skills such as Movement, Might, or Acrobatics, casting a spell with a material-only component, melee attacks with a reach weapon, etc. In general, melee attacks by non-reach weapons, even light ones, are not affected by high winds. Spellcasting in bad wind (or even just heavy rain, see below) requires a Caster Check for each spell attempted, with the penalty described above for the type of spellcasting. If you can manage to cast spells without needing verbal, somatic, or material components, you may cast such spells without a check. And, wow, nice trick.
2   Checked Size: Creatures of this size or smaller are unable to move forward against the force of the wind unless they succeed on an Average Might skill check against their own level (if on the ground) or an Impossible Movement skill check if airborne.
3   Blown Away Size: Creatures on the ground are Pushed in the direction of the wind by one square each round per level they fall below their size/windspeed threshold. IE, a Small creature in a tornado suffers 3 squares of Push each round. They may fall Prone to negate this movement if they wish, and can resist with forced movement resistance.


Light or moderate rain is not bad enough to materially change the effects of the Winds table above. It may lower heat effects by one level if in a hot climate, so that's even a positive, as long as you don't mind being soaked....

Heavy Rain

Heavy rain adds -1 to all the Physical Action penalty numbers from the Wind table. This means that even in Light wind, you get a -1 to both careful and powerful physical actions, which makes picking a lock in a torrential downpour even less fun than ever, and spellcasting just generally sucks. (We recommend all casters in typhoon climates to seriously consider Uncanny Concentration.) Heavy rain also limits visibility to all senses, offering concealment to things further than 60 feet away, and total concealment after 120 feet. Bleah.

Dangerous Liquid

Going for a swim in a vat of urine, or swimming through a pool of blood, or staying afloat in a lake of pus, are all thoroughly unpleasant things. See the Movement skill for trying to swim around in such unpleasant surroundings.

As a general rule, being immersed in a Dangerous Liquid inflicts the Singed condition, that cannot be removed until you leave the dangerous liquid. The damage dealt is based upon the liquid at the GM's discretion. The CR of the Singed condition is the CR of the area, or the CR of the immersed player, whichever is higher.

Deadly Liquid

Being immersed in a deadly liquid is bad. Going for a swim in boiling water, or swimming through a pool of acid, or staying afloat in a huge drum of molten liquid wax in a mad alchemist's Waxwork Factory, are all generally terrible things. Note that lava is a separate entry. Lava is even WORSE. See the Movement skill for trying to swim around in such unpleasant surroundings.

As a general rule, being immersed in a deadly liquid inflicts the Burned condition, that cannot be removed until you leave the deadly liquid. The damage dealt is based upon the liquid at the GM's discretion. The CR of the Burned condition is the CR of the area, or the CR of the immersed player, whichever is higher.


Catching on Fire

Characters exposed to burning oil, bonfires, forest fires, and non-instantaneous magic fires might find their clothes, hair, or equipment on fire. Spells with an instantaneous duration don't normally set a character on fire, since the heat and flame from these come and go in a flash. Spells that specifically set you ablaze always include the effects in the spell description.

But what if you get caught in a siege that ends with the entire city being consumed in a blaze? This may progress to the level of a Wildfire, see above.

But suppose you've been swimming in a vat of brandy (see Dangerous Liquids, above), and after you get out, soaked in highly flammable alcohol, THEN you get hit with a fire effect? It is entirely reasonable that you would burst into flame.

Characters at risk of catching fire are allowed a Hard reflex saving throw of their CR to avoid this fate. If a character's clothes or hair catch fire, he suffers the Singed condition with the damage based on his CR, or the CR of the effect which caused the ignition, whichever is higher. Removing this singed condition is done as normal, although at GM discretion you may need to do other things in your given set of circumstances.

Extinguish / Douse a Fire

In general terms, a gallon of water, cool ash, sand, dirt, and similar substances can put out the flames on five square feet of surface. To extinguish the flames in a standard square thus requires five gallons of water, or a large pail. A Size Medium Character has roughly 25 square feet of surface, and thus requires five gallons to put out. Size Small requires only a gallon, size Large requires forty gallons, Size Huge requires 320 gallons, etc. A large pail holds five gallons, a normal barrel or a deep tub holds fifty gallons.

A character on fire may automatically extinguish the flames by jumping into enough water to douse himself. Similarly, tossing flaming objects into a body of water larger than their Size extinguishes them. If no body of water is at hand, rolling the person or object on the ground or smothering the fire with cloaks will do the trick after one full round action spent on the activity.


Quicksand is nothing more than sand or loose soil that is supersaturated with water. This effect allows creatures to sink into the mixture much as if they're settling into nothing more than silty water, but then requires them to fight the crushing weight of sand as if they had been buried alive to escape.

Patches of quicksand present a deceptively solid appearance to all senses except Tremorsense, appearing as undergrowth or open land. To spot quicksand before falling into it requires a Hard DC Survival Skill roll or an Impossible DC Perception skill roll, with the CR of the check being the CR of the area or the character's CR, whichever is higher. If the character has Tremorsense, he spots the quicksand automatically as soon as it is within range.

Falling into quicksand is handled as trying to Swim in a Dangerous Liquid (see above), with the Singed condition inflicting Winded damage. The real danger of quicksand is the nigh-impossibility of getting out of it without external aid. If a character is in Quicksand, it takes an Impossible Might Check against their CR plus 1 to climb out if they can grab something solid outside the quicksand. If there is nothing to grip, they are not even allowed a roll to escape.

Pulling out a character trapped in quicksand can be difficult. A rescuer needs a branch, spear haft, rope, or similar tool that enables him to reach the victim with one end of it. Then he must make a Challenging Might Skill check against a DC set by the CR of the victim to successfully pull the victim free. Failure means they remain stuck, and suffer another round of Singed....

Starvation and Thirst

See: Survival Skill


A character who has no air to breathe can hold their breath for 1 minute. After 1 minute, they receive the Gagging condition as they begin to run out of air.

For each additional minute they remain without air, the condition worsens, first to Choking, then Asphyxiating.

Unless they can remove the Asphyxiating condition, they die promptly.

Slow Suffocation

A sized-medium character can breathe easily for 6 hours in a sealed chamber measuring 10 feet on a side. After that time, the character takes 1d6 points of winded (physical, uncommon) damage every 15 minutes. Each additional Medium character or significant fire source (a torch, for example) proportionally reduces the time the air will last. Small characters consume half as much air as Medium characters, Large characters consume twice as much.


Lightning Storm

Despite the flash and thunder of a severe lightning storm, the danger from the lightning is very small. If a character is struck, the damage is 1d6+1 of electricity (energy, common) damage per CR of the area, or the character's CR, whichever is higher. A much larger danger is the risk of falling trees, which are defined as Falling Objects, typically size Gargantuan or bigger, falling a distance equal to their height (which can easily exceed 100 feet), with a -1 per die since they are brushy and 'soft'. The GM adjudicates all effects, of course.


A sandstorm can represent the fine grit we are familiar with, or it may be caused by icy spicules on a glacier, or driving needles of bone in a vast graveyard, or tiny spores in a giant field of poppies, or many other effects.

A sandstorm reduces visibility to 1d10 squares (5 feet to 50 feet) (the GM may check as often as each round in combat or once a minute out of combat to see how bad the seeing is) and provides a -4 penalty on Perception checks on top of any minuses caused by the level of the Wind effects. A sandstorm does not cause miss chances in combat or offer concealment. A sandstorm deals 1d3 points of environmental buffeting (physical, uncommon) damage per hour to any creatures caught in the open, on top of any Heat or Cold effects the environment may be inflicting.


A Tsunami is just unfair. A quiet, tropical paradise one moment, and the next, a wall of water tries to kill you.

A Tsunami is an Avalanche, of water, and if you are buried, you immediately begin Suffocation. See the Avalanche and Suffocation rules above.

So unfair....


This looks inviting....

When the world decides to explode in fire and poison, one of the most dramatic natural disasters results: a volcano. Volcanic eruptions offer a wide range of options for the GM, including lava, lava bombs, poisonous gases, and pyroclastic flows. GMs might also consider presaging a dramatic volcanic eruption with existing hazards, like avalanches and minor earthquakes.

Volcanic Climate

The area around a volcano, and especially in a volcano, are subject to environmental heat. The level of heat is left to the GM, but it generally starts as hot a good distance away and proceeds to the highest level of environmental heat on the outer slopes. Inside a volcano is usually handled as being inside a Wildfire. Yuck.


Lava or magma is a strange sort of terrain. It can be very runny, or thicker than pitch. As such, the GM adjudicates whether you can move with Walk, Burrow, Vaulting, Teleport, or other surface/material interacting movement types on lava. In all cases, Lava counts as difficult terrain, as does all the air above it to the limit of Altitude Effects coming into play, due to savage up-blasts of heated air erratically pummeling flyers.

Being adjacent to Lava, touching it or not, inflicts the Immolated condition doing fire damage according to the CR of the area or the characters CR, whichever is higher. Just being within fifteen feet of a lava square inflicts the Singed condition until you move away.

For the difficulties of swimming in a very dense but very runny lava, see the Movement skill.

Burrowing through a stiff lava is possible as if it were soft earth, except for the whole Immolated condition it inflicts. Being completely surrounded by lava (swimming down into it if its runny, or burrowing through it if its stiff) DOUBLES the amount of damage the Immolated condition inflicts, as there are few things more insane than swimming in lava.

Immunity or resistance to fire works against lava. A creature immune or resistant to fire might still drown if completely immersed in lava (see Suffocation).

Lava flows and that great classic, the lava lake, are usually associated with nonexplosive eruptions, and can be a permanent fixture of active volcanoes. Most lava flows are quite slow, moving at 15 feet per round. Hotter flows move faster, achieving speeds up to 60 feet per round. Lava in a channel such as a lava tube is especially dangerous, moving too fast to escape, and is treated as an Avalanche...of FIRE. Getting hit with a lava flow inflicts full Avalanche damage AND the Immolated condition. If you are buried by a lava flow, you take double Immolation damage AND immediately begin to Suffocate. Eeesh....

Creatures overrun by a lava flow must make a save as per the Avalanche rules or be engulfed in the lava, taking double Immolated damage. Success indicates that they are in contact with the lava (and thus Immolated) but not immersed.

Lava Crust

It's very common for lava lakes and lava flows to have a solid crust. Walking on a lava crust is exactly the same as moving on ice, except that since you are within 15 feet of lava, you gain the Singed condition and of course, you are at risk from Heat, not Cold.

Lava Bombs

Blobs of molten rock may be hurled several miles from an erupting volcano, cooling into solid rock before they land. A typical lava bomb is treated as a spectacularly deadly Falling Object, typically being size Small and up, falling from 200 feet high, and gaining +2 points of damage per die with the caveat that the bonus damage is Fire damage. The minimum damage from a Lava Bomb is thus 21d6 of falling damage plus 42 points of fire damage, Reflex save for half, and a Titanic+ lava Bomb does 54 dice of Falling plus 108 of fire, to a huge area. To make things even worse, if a character is struck by a Lava Bomb size Huge or larger and they fail their saving throw, they are considered to be buried, and take merely the Burned condition in addition to being Pinned. This is sufficiently unpleasant to make ANY character wary around a busy volcano!

Volcanic Gas

The area around a volcano is usually treated as High Altitude with the Inimical Gas option, although there may be pockets of Heavy Smoke from the Wildfire rules. All these effects are detailed above. Being inside a volcano is Heat at a minimum, and more likely the same as being trapped in a Wildfire.

Pyroclastic Flow

Some volcanic eruptions create a devastating wave of burning ash, hot gases, and volcanic debris called a pyroclastic flow that can travel for miles. Treat a pyroclastic flow as an avalanche combined with a wildfire, that also inflicts the Burned condition doing Fire damage to all those struck by or buried within it. If you fail the save, the Burned damage is doubled until you can escape. Note that because a pyroclastic flow is also a fire, you cannot fly above it to escape, taking heavy smoke damage.


See the Movement skill for most interactions with fairly shallow (less than a hundred feet) water, or similar fluids.

Very deep water is not only generally pitch black, inflicting blind to all light-depended visual senses, but worse, deals water pressure crushing (physical, common) damage of 1d6 points per minute for every 100 feet the character is below the surface. Very cold water also deals 1d6 points of environmental cold (energy, common) damage per minute of exposure.


If you don't bring a supply of air, or have some way of breathing in the water or other liquid you're swimming through, you start to Drown after one minute below the surface. Popping back up before a minute is up to take a breath is allowed and strongly encouraged. Note that a character with a Swim speed or lots of Movement skill can get REALLY deep in a minute of swimming, so see the rules above for the crushing effects of pressure damage, and be sure to bring a light.

Drowning in water is exactly like Suffocation. See above for those rules.

Note that it is possible to drown in substances other than water, such as sand, quicksand, fine dust, gigantic piles of gold and jewels, red-hot flaming volcanic ash, blood, acid, and silos full of grain, just to name a few possibilities.

Fast-Flowing Water

Large, placid rivers move at only a few miles per hour, so they function as still water for most purposes. But some rivers and streams are swifter; anything floating in them moves downstream at a speed of 10 to 40 feet per round (typically set in advance by the GM, although eddies and rapids might have varying water speeds every few seconds). This is treated as a Push in the downstream direction that cannot be opposed by Forced Movement resistance, unless you can get your feet on a solid bottom. The fastest rapids send swimmers bobbing downstream at 60 to 90 feet per round. See the Movement skill for swimming in rough water.

Swept Away

Characters swept away by a river moving 60 feet per round or faster suffer according to the Collisions rules as they are bashed about in the water. A character may make a Might check as if trying to catch themselves while falling as they are swept away. The distance moved each round before the Might check is made is set each round by rolling a d8 times five feet, and that sets the difficulty of the Might check (this can be less than DC20 in this case). When a Might check succeeds, they arrest their motion by catching a rock, tree limb, or bottom snag, and can escape the sudden flow.


A Flashflood is just like a Tsunami, except it can happen almost anywhere. Yay! A horrible avalanche of water and debris that Suffocates anyone it catches! Yay!